(1) Field of the Invention
This invention generally relates to towed acoustic line arrays and more particularly to a device for breaking-up large eddys developed when an acoustic line array is towed in a body of water such as an ocean.
(2) Statement of the Prior Art
When an acoustic line array is towed in a body of water such as an ocean, its sonar system is ambient-noise limited at high frequencies. This means that further self-noise improvements at high frequencies are not possible. However, at low frequencies the sonar system is subject to a variety of undesirable noise mechanisms which, if reduced, would improve the performance of the system. One of the most troublesome low frequency noise sources is the flow noise, i.e., the pressure fluctuations inside the turbulent boundary layer, hereinafter designated as the TBL, about the towed array. It is thus desirable to reduce the flow noise to improve the performance of the sonar system of the towed array. Very little seems to have been done to address this problem although spoiler wings and Large Eddy Break-up Devices (LEBUD) have been investigated for drag reduction and stability of flat plates.